| In this paper, the hot continuous rolled (HCR) and isothermal forged (ITF)technologies are used for preparing GH4169 superalloy, and the influences of deformationand heat treatment technologies on the mismatch, mechanics and creep properties of alloyare investigated by means of mechanics performance measurement and microstructureobservation. Thereinto, the strain state on the interfaces between the phases in the alloyspropared by different technologies is understood by means of measuring the latticeparameters ofγ,γ′andγ〃phases, and the deformation and fracture features of the differentstates alloys during tesile and creep are investigated by means of tensile and creep tensileproperties measurement. And some results are obtained given as follows:Microstructure of GH4169 alloy consists of theγ,γ′andγ〃phases. After direct aged(DA) and long-term aged (LTA) treatment, the volume fraction ofγ〃phase in the alloyincreases gradually, and the one ofγ′phase decreases. Wherein, theγ′phase in the alloydisplays the partcle configuration, and theγ〃phase is precipitated in theγmatrix in theform of the flat-like shape. Compared with ITF-GH4169 alloy, theγ,γ′andγ〃phases inHCR-GH4169 possess the bigger parameters and misfits in between the phases. Afterstandard heat treated, theγ′andγ〃phases are coherently embedded in theγmatrix, andpossesses a bigger lattice strain. After direct aged (DA) and long-term aged (LTA), theparameters of theγ,γ′andγ〃phases in the alloy diminish slightly, but the absolute value ofthe mismatch between theγ/γ′phase andγ/γ〃phases increases slightly. And compared to GH4169 alloy, the mismatch between theγ/γ′phases andγ/γ〃phases in GH4169G alloyincreases slightly. After direct aged (DA), the lattice parameters ofγ,γ′andγ〃phases inGH4169G alloy increases slightly, and the mismatch between the phases decreases slightly.After long-term aged (LTA), the lattice parameters and misfits ofγ,γ′andγ〃phases inGH4169G alloy diminish slightly.Compared to the ITF alloy, HCR(WC) alloy has a smaller grain size, and HCR(AC)alloy has a larger grain size. After direct aged (DA), significant amount of the fineγ″phaseare dispersedly precipitated in theγmatrix of GH4169 alloy. After standard heat treated(ST) and long-term aged (LTA) treated, some needle-like or shorter rod-likeδphase areprecipitated along the boundaries. After adding trace P and B, the grain size in GH4169alloy increases slightly, and some shorter rod-likeδphase are precipitated along theboundaries or within the grains.In the ranges of the experimental temperature, the yield and tensile strength ofHCR-DA or HCR-ST-GH4169 alloy decreases gradually with the increase of temperature.The twinning and double orientation slipping of dislocations are thought to be the maindeformation mechanism of the alloys during tensile measuring, and the activated twinningplanes are identified as {111} plane. Thereinto, in the ranges from room temperature to 500℃, the double orientation slipping of dislocations is thought to be the main deformationmechanism, and the twinning is the dominant deformed mechanism as the temperature rise,but a few dislocation is activated in ST-GH4169 alloy during tensile measuring. In thelatter stage of the tensile testing, the denser dislocations are piled up in the region near theboundaries to bring out the stress concentration, which may result in the initiation andpropagation of the cracks along the boundaries to occur the intergranular fracture.In the ranges of 650℃~670℃and 700MPa~750MPa, the creep activation energies ofITF-DA-GH4169 alloy, HCR(WC)-DA and HCR(WC)-DA-LTA-GH4169 alloys arecalculated to be 519.0 kJ/mol, 610.0 kJ/mol and 584.6 kJ/mol, respectively, the stressexponents are calculated to be 18.5, 15.4 and 16.3, respectively, and the creep activationenergies of ITF-DA and ITF-DA-LTA-GH4169G alloys are calculated to be 594.7 kJ/mol and 550.3 kJ/mol, respectively, the stress exponents of the alloys are calculated to be 15.8and 17.8, respectively. Compared to other preparing technologies, hot continuous rolled(HCR) preparing alloy after direct aged (DA) displays a better creep resistance, and thecreep lifetime of the alloy at 700MPa / 660℃is measured to be 127 h. During creep, theonly twinning is activated in ITF-DA-GH4169 alloy, the deformation mechanisms ofHCR-DA-GH4169 alloy and GH4169G alloy is identified as the twinning and doubleorientation slipping of dislocations activated within the twinning, and the twinning planesis identified as {111}. Wherein, the"prestored"dislocation formed during HCR of the alloymay activate the single orientation and double orientations slipping of creep dislocations,which may loose the stress concentration to improve the creep resistance of HCR alloy andprolong the creep lifetimes.The traces P and B may decrease the diffusion ability of the element Nb in the matrixto delay the coarsening ofγ" phase, especialy, the pinning effect ofδphase precipitatedalong the boundaries may improve the deformed resistance of alloy during isothermalforged. Therefore, the twinning and a few slipping of dislocation with different oriented areactivated in GH4169G alloy during isothermal forged (ITF). During creep, the grainboundaries in the alloys prepared by different technologies are thought to be the weakerregion of the creep resistance. And the densities of the twinning and dislocations in alloysincrease as the creep goes on, althought the grain boundaries my hinder the dislocationsmovement, the dislocations accumulated in the boundary regions may bring out the stressconcentration which may promote the initiation and propagation of the cracks along theboundaries in the later stage of creep. Wherein, the intergranular fracture during creepoccurs in the ITF-GH4169 and HCR-GH4169 alloys, and the feature of the mixed fractureappears in the ITF-GH4169G alloy.
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